Monster Academia
by Otakufanlover
Summary: Based off of Monster Musume. Izuku Midoriya's life was not anything special that is until he signed up for the Interspecies Exchange. That is when his life changed forever.


Summary: Based off of Monster Musume. Izuku Midoriya's life was not anything special that is until he signed up for the Interspecies Exchange. That is when his life changed forever.

Warnings: Yaoi Monster Boy Harem. Human with different species of Monster Boys. Mpreg.

This is the sixth of my birthday gifts for my good friend, PaperFox19. I hope he likes it.

 **Chapter 1**

Izuku Midoriya was sleeping peacefully until his alarm went off. He sleepily fumbles to shut it off. His hand finally finds the alarm and hits the off button. Izuku turns over to get up when he sees someone in his bed with him. It was Katsuki Bakugou the Monster Boy he was put in charge of, thanks to him signing up for the Interspecies Exchange program. This program was put into effect not too long ago.

This program allows Monsters to come and live in the Human world. It allows them to be around Humans with no problems, but they have to be with and live with a host family. A Monster cannot stay in the Human world without a host family to take care, and be responsible for them. If the Monster does not find a host family they will be sent back to their home land.

There are rules to protect both the Monster and the Human. First Monsters cannot hurt Humans and vice-versa. If a Monster hurts a Human they will be banned from staying in the Human word. If a Human hurts a Monster they will be put in prison, and the people in charge will try and find the Monster a new host family to stay with. The second thing is Humans and Monsters can fall in love and have sex/mate, but it has to be consensual on both sides. The Monster cannot force or hypnotize the Human to mate with them while the Human cannot force or manipulate the Monster into having sex with them.

The case worker assigned to the household will be the one to determine if the relationship is healthy, and if they can have sex/mate. Mating is marriage for Monsters, so Humans have been tricked into having sex with Monsters and then finding out they are mated and stuck with them for life. This is why there needs to be a mediator for this situation, but there have been many cases where Monsters and Humans have mated and are very happy together.

'I guess that's why on the questionnaire I filled out it asked if I would want to date the Monster if I got selected for the program. It also asked what gender I would want.' Izuku thinks as he stares at Katsuki. 'He's cute when he is sleeping.'

Monster Info

Katsuki Bakugou is an Incubus. Incubi are the male counterpart of the Succubus. Incubi feed off of Human's energy during sex. They can either eat by having sex with the Human themselves or induce the Human to have a sex dream, and feed off of that. They have horns on their heads, and a pointy tail with a spade shape tip. Incubi like Succubi come in different colors. Their horns, wings, and tails come in different colors; and, their horns are usually different colors from their wings and tails. Their wings come out of their lower backs, making them look like a tramp stamp. They look like bat wings. Their tails come out of their tail bone. Horns come out of the back of their heads, next to each other. They have pointy ears like Elves.

The colors of their wings and tails also mean different things. Red Means Rough Gay Top. Orange Means Top. Yellow Means Top, But Open to Bottoming. Green Means Switcher. Blue Means Bottom. Purple Means Power Bottom. Pink Means Hyper Sexual. Black Means Kinky Sex/BDSM. And last, White Means Pure Virgin.

End Monster Info

Katsuki happens to have blue wings and tail. His horns are black. Katsuki was a bottom Incubus, and man does Izuku know it. Katsuki was always jumping Izuku trying to get him to have sex with him. Izuku was hesitant to have sex with Katsuki just yet. He was talking it over with his case worker, Naomasa Tsukauchi, on if it was okay to mate with him. Yes, that's right, mate with him. Izuku had fallen in love with Katsuki from the months he had been with him. Now he wanted to take it to the next level, but first he needs Naomasa's permission. Which he will be talking to him about today. But first he had to get up.

"Kacchan." Izuku urges. "It's morning. Wake up."

"Five more minutes…" Katsuki grumbles.

"Come on. I need to start on breakfast." Izuku encourages. Katsuki perked at the mention of "breakfast." He then started to stroke Izuku's morning erection in his boxers. Izuku jumps when his hand comes in contact with is cock.

"Kacchan!" Izuku yelps. "What are you doing?!"

"I am getting my breakfast ready." Katsuki answers. He pulls Izuku's boxers down, revealing his hard cock. Izuku groans when his cock feels the cool air.

"Itadakimasu." Katsuki says, before he takes Izuku's cock into his mouth. Izuku moans when he feels his hot, wet, mouth on his cock. Katsuki starts to give Izuku the best blow job he has ever had. Incubuses are the best when it comes to sex.

"Ah…Kacchan." Izuku pants. "I'm going to cum soon."

Katsuki just sucked him harder. He wanted his breakfast. Izuku moans and pants as Katsuki sucks him harder, swirls his tongue along his cock. It felt so good.

"I'm cumming!" Izuku moans. He then releases into Katsuki's waiting mouth. Katsuki eats his cum with relish. He loved eating Izuku's cum.

"Gochisousama." Katsuki says, licking his lips. His energy was reenergized, as could be seen by the healthy sheen of his skin. Izuku looked a little paler afterward since some his energy was taken.

"I am going to need to eat more protein today." Izuku sighs. He gets up to get cleaned up and to get started on his day. Katsuki was laying on the bed, content, with his tail lazily waving in the air with his wings twitching every now and then.

Izuku heads to the kitchen to start on breakfast. He definitely needs it after having some of his energy taken, but he did not mind having his Kacchan feed off of him.

"I really need to talk to Naomasa today." Izuku comments, as he starts cooking breakfast. He really wanted to claim his Kacchan fully.

"I hope you have not mated with Katsuki yet?" A voice asks, startling Izuku. Izuku turns around and sees Naomasa sitting at his counter drinking some of his coffee.

"Naomasa! You scared me." Izuku says. "No, we have not mated yet."

"Oh, yet, huh?" Naomasa hums. Izuku finishes making the breakfast and puts it onto some plates.

"Yes, I have been wanting to talk to you about going through the process of getting to mate with, Katsuki." Izuku explains.

"Ah. He has been in your care for a while now. If you want to go through the process of mating him. I will put it in the system. It will take a week though." Naomasa explains.

"Thank you so much!" Izuku says with a smile. Naomasa smiled from seeing how happy Izuku was.

"I have been meaning to ask you." Naomasa starts.

"Oh? What about?" Izuku asks.

"Are you planning on taking in anymore Monsters?" Naomasa asks.

"I haven't really thought about it to be honest." Izuku says.

"I see." Naomasa says.

"But, I would not mind taking in more Monsters." Izuku smiles.

"That's nice to know." Naomasa says with a smile. Izuku tilts his head in confusion.

"No! Deku is mine!" Katsuki yells, as he come into the kitchen and clings to Izuku. He glares at Naomasa for daring to mention more Monsters for Izuku.

"It's okay Katsuki." Izuku reassures. "Even if more Monsters come to live with us, you will still be my number one."

"Humph, fine." Katsuki grumbles. Izuku and Naomasa smile at his tsundere attitude. When they finished eating, Naomasa stands up to leave.

"Well, I will put in the paper work for the mating process." Naomasa says. "I will see you soon, and let you know."

"Okay, thank you again, Naomasa." Izuku says, as Naomasa walks out of the house.

"So what are we going to do today, Deku?" Katsuki asks while cuddling Izuku.

"I was thinking we could go out today." Izuku says. Katsuki jumps up.

"Like a date?!" Katsuki asks in excitement. Izuku laughs.

"Yeah, like a date." Izuku answers.

"Okay, let me go get dressed." Katsuki says, as he runs to their room to change out of his night shirt and boxer briefs.

"He is so cute." Izuku chuckles with adoration. He then cleans up the kitchen before they leave.

-Shopping District-

Izuku and Katsuki were walking, looking at the different stores looking for the ones who sold clothes for Monsters. Izuku looked over at Katsuki and smiled at how excited and happy Katsuki was. Izuku blushed at what Katsuki was wearing. Katsuki was wearing a red vest with hearts cut in it to expose the nipples. Red fingerless gloves that go up his arm to his elbow. A skimpy undergarment, the crotch part can barely cover his cock, but hug their balls nicely, 3 straps stretch over to hug their plump ass. A black garter on the left leg, and knee high stocking on the right. His blue wings hanging out of his lower back proudly.

He was getting different looks, ranging from curious to disgust from the other Humans who were shopping. Izuku stiffens in anger at the looks of disgust and lust. Katsuki was _his,_ how dare they think they could disrespect or have him.

"Let's get this date underway, Deku!" Katsuki cheers. He grabs Izuku by the hand and drags him excitedly through the shopping district. Thus, shaking Izuku from his possessive, murderous thoughts.

They go and eat at a Monster friendly restaurant. They then went to an arcade and played some games. Before they left, Katsuki wanted a plush from a claw machine. He wanted the black bunny looking one with the bat wings and pointy spade tail with a red ruby on its forehead, but was having a hard time getting it.

He had gotten 9 different plushes from the claw machine, but not the one he wanted. The first one he got was a little lion with orange like flame mane with a helmet on its head with a blue symbol on it. The second and third plush he got came as a pair, a black cat and a white cat both with crescent moons on their foreheads. The fourth one he got was a slim, cute blue dragon. The fifth one was a polar bear in an orange boiler suit with a smiley symbol on it. The sixth one was a grey and white fur hedgehog. The seventh one was, what looked like a puppy with lasers coming out of its eyes. The eighth one was a brown fluff ball with green claw hands and feet, with white wings, and eyes. The ninth and last one, so far, was a black piglet with a yellow scarf around its neck.

Izuku got a bag from an employee of the arcade to put the plushes in. He then watched Katsuki struggle to get the plush he wanted, before he stepped in.

"Having trouble, Kacchan?" Izuku asks. Katsuki pouts.

"Yeah, I really want this one, Deku." Katsuki says.

"Here." Izuku says, moving in front of the claw machine. "Let me try."

Izuku than proceeds to get the plush from the claw machine, much to Katsuki's delight.

"Yes! Thank you, Deku." Katsuki thanks, as he cuddles the plush.

"No problem." Izuku says, smiling softly at how cute Katsuki is.

Than to Izuku's embarrassment, they went to a lingerie shop. One of the shops that caters to Monsters.

"I-I'll wait outside." Izuku stuttered blushing, and turning to go back outside. Katsuki grabs him and drags him into the shop.

"Naomasa said we have to be together at all times." Katsuki reminds him. He then walks up to an employee and asks. "Excuse me, do you have a section for Incubuses?"

"Yes, over here." The employee says, as she leads them over to the section. "Take your time."

"Thank you." Katsuki says, as he starts to browse. Izuku was looking around. It was nice to have shops who cater to Monsters. The employees were nice also. Than he had a thought.

'Does Katsuki wear underwear? He seems to wear something that looks like underwear out in the open.' Izuku thinks, while blushing some more.

"Deku, which one do you like better?" Katsuki asks, breaking Izuku out of his train of thought. He looked at what Katsuki was holding and about died. He was holding a blue babydoll, lace negligee in one hand. In the other hand he was holding a red negligee dress type with black fur around the chest and bottom hem areas.

"I-I don't know much about lingerie or negligee." Izuku blushes. "Get what you want."

"Well, I want to get what you like, Deku. So I want you to look at them and choose the ones you like. I want to wear whatever you like." Katsuki says, with a cute blush.

"You look good in anything, Kacchan." Izuku says. "But I do think you would look amazing in both of those."

"Really?" Katsuki lights up. "I will get them then."

They pay for the items and then leave the store. They were walking peacefully down, with Katsuki cuddled up to Izuku's side, the sidewalk when they were stopped by a rude and disgusting couple.

"Whoa! What is that?" The woman of the couple says with a laugh.

"Damn! It is cuddled up to that boy!" The man of the couple scoffs.

"Talk about gross." The woman says.

Katsuki was shaking in anger. His fists were becoming fire. Izuku saw this and took action.

"I don't know what your problem is, but it stops now." Izuku growls. Shocking everyone around him, since Izuku looks like a soft and sweet guy. Which he is, but you do not mess with what is his.

"Who do you think you are talking to boy?" The man says, taken back by Izuku's change in attitude.

"I am talking to you, _sir_." Izuku stressed the word sir. "I do not like how you were talking about my mate. Either apologize and leave, or just leave."

The couple is taken back by Izuku calling them out on their shit. Nobody had done this before.

"Fine. We do not need to be around a freak lover anyway." The woman sneers.

"Yeah, come on babe." The man says. And as the cowards they were, they left with their heads down. Izuku relaxes when the couple was out of sight. He turns to Katsuki.

"Deku… that was so… sexy!" Katsuki pants, feeling warm. Blue winged Incubuses loved to be dominated, so Izuku's dominate display was getting Katsuki hot and bothered. Izuku notices this.

"Let's go home now." Izuku says, wanting to get home so Katsuki can cool down.

-At Home-

Moans, pants, and whines could be heard in the house. Katsuki was withering on the bed naked. Izuku helped by using a large dildo on him since he could not mate with him yet.

"Ah… I… want you, Deku!" Katsuki whines.

"I'm sorry love, but we cannot mate yet. Soon." Izuku reassures. He then twists the dildo and strikes Katsuki's sweet spot.

"Yes!" Katsuki screams in pleasure. Izuku thrusts the dildo a few more times and then Katsuki comes. Katsuki then falls asleep, tired from the long day they had. Izuku cleans him up and dresses him in his pajamas. After doing somethings around the house, he lays down in bed with Katsuki.

'I can't wait till you are really mine, Kacchan.' Izuku thinks, looking at Katsuki. He then falls asleep. Not knowing what tomorrow would bring.


End file.
